I'm thinking raccoon or opossum,. I had three birds in an enclosure. I've never had a problem before with anything going after my chickens but this morning when i went out to feed them one bird was completely gone, one was dead with its leg chewed open and there was one egg eaten, with many others left behind. Feathers were everywhere and i notice a very small one inch ripped hole in the canvas fabric covering i had over the run, the same size as the wire mesh behind it. I'm leaning towards an opossum but with these were large adult birds and i can't imagine a raccoon taking off with an entire adult bird. There were no dug up holes from underneath so i'm figuring whatever it was had to be a climber and a strong one at that.